1:30–2:30 pm ERC 445
“Probing LSS with Large Galaxy Surveys: Systematics and Estimators”
Studying cosmology with large galaxy surveys requires an unprecedented understanding and mitigation of systematics—a challenge that can be addressed on two fronts: quantification of the impacts of systematics, and new tools to mitigate them. Addressing the first, I will discuss work on the artifacts induced by the observing strategy for the Large Synoptic Survey Telescope (LSST) and present large dithers as an effective mechanism to mitigate the induced artifacts (Awan et al. 2016, ApJ, 829, 50)—a result that has now been adopted for the LSST observing strategy. I will also quantify the impacts of Milky Way dust on Large-Scale Structure (LSS) studies and the resulting cosmological parameter estimation. As for new tools, I will present a galaxy angular correlation function estimator that corrects for sample contamination arising from photometric-redshift estimation (Awan & Gawiser, 2019, submitted to ApJ); our framework allows for optimization of the estimator to improve the precision of cosmological parameter estimation. While these techniques are motivated by preparations for LSST, they are applicable to DES, DESI, HETDEX, Euclid, and WFIRST.
Astronomy & Astrophysics Colloquium: Dan Stark (Univ. of Arizona) "Galaxies in the Reionization Era"
3:30–4:30 pm ERC 161
Over the past decade, deep infrared images have pushed the cosmic frontier back to just 500 million years after the Big Bang, delivering the first large sample of galaxies at redshifts 7
7 galaxies from ALMA, Magellan, and Keck has begun to sharpen our understanding of this reionization process while also providing a glimpse of the physical nature of early galaxies. The spectral features we are detecting at z>7 are unlike what has been seen at lower redshifts, hinting at a population of low mass galaxies undergoing frequent bursts of star formation. Surveys at lower redshift have begun to reveal insight into the ionizing efficiency of this population of low mass galaxies, providing quantitative constraints on the production and escape of ionizing radiation. In this talk, I will review the latest in observational efforts to understand galaxies in the reionization-era and discuss remaining challenges that must be addressed in advance of JWST.
3:30–4:30 pm ERC 161
After a series of null results from the LHC and large direct detection experiments, dark matter remains frustratingly mysterious, and much of the canonical heavy WIMP parameter space is now ruled out. In this talk, I will give an update on the status of the LZ experiment, and discuss an idea to expand the parameter space that can be probed by large liquid xenon TPCs like LZ by adding hydrogen to the target, opening up sensitivity to WIMP masses well below 1 GeV.
Reception following colloquium in the Hubble Lounge (ERC 501).
2:00–3:00 pm ERC 419
11:00 am–12:00 pm ERC 401
3:00–4:00 pm ERC 576
11:00 pm KPTC 106
90th Compton Lecture: Reed Clasey Essick, KICP, “What to Do When Gravity Waves”
3:00–5:00 pm Hubble Lounge (ERC 501)
9:00 am–12:00 pm ERC 576
8:00 am–5:00 pm Gleacher Center